<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>可单击按钮 </title>
	</head>
	<body>
	 <form action="form.php" method="post"> 
		 <input type="button" value="点我！" onclick="alert('这是一个按钮！')" /> 
	</form> 
	</body>
</html>